Drum-type segregating apparatus



March 3, 1964 E. G. HILLS DRUM-TYPE SEGREGATING APPARATUS Filed June 19, 1962 \NVENTOR Ema 7 HILLS BY ATTORNEY United States Patent 3,123,216 DRUM-TYPE SEGREGATING APPARATUS Eric George Hills, London, England, assignor to Her Majestys Postmaster General, London, England Filed June 19, 1962, Ser. No. 203,570 Claims priority, application Great Britain June 20, 1961 6 Claims. (Cl. 209-86) The present invention relates to segregating apparatus for segregating from a quantity of differently sized articles, those articles having at least one dimension less than a predetermined dimension. The invention is more particularly concerned with the sorting of postal mail in which it is required to segregate letters and like thin postal items from a miscellaneous quantity of postal mail.

In US. Patent No. 2,895,610, dated July 21, 1959, there is described a segregating apparatus for segregating from a quantity of different sized articles, those articles having at least one dimension less than a predetermined dimension, the said apparatus comprising a drum-shaped receptacle supported for rotation about its axis so that the peripheral wall thereof provides an upwardly moving surface, the said peripheral wall being formed by a plurality of overlapping flaps extending longitudinally of the drum, the overlapping portions of adjacent flaps being spaced to provide longitudinally extending slots of a width equal to the said predetermined dimension.

In order to provide for the continuous segregation of items of mail fed into one end of the drum it is necessary that the axis of rotation thereof be downwardly inclined from said one end so that upon rotation of the drum items not discharged through the slots progress lengthwise of the drumto be discharged at the other end thereof. This presents the disadvantage that considerable head room is required for installing the drum and somewhat elaborate supporting structure and drive means are necessary.

A further disadvantage is that although the width of the slots limits the thickness of items which can pass through them, the slots extend longitudinally of the drum over the entire length thereof so that items of any length less than the length of the drum but having a thickness less than the width of the slots will pass through the slots and thereby be segregated.

It is an object of the invention to overcome the aforementioned disadvantages and according to the invention apparatus for segregating from a quantity of letters or similar flat articles, those articles or similar fiat articles of less than a predetermined thickness and having at least one linear dimension less than a predetermined dimension, comprises a drum-shaped receptacle for containing said quantity of letters or similar fiat articles, supported for rotation about its axis and means for rotating the drum, the said drum having a peripheral wall formed by a plurality of elongated panels extending lengthwise of the drum and overlapping each other along their longitudinal edges, each panel being formed with V-shaped corrugations extending transversely thereof at an angle inclined with respect to the longitudinal axis of the panel and mating with the corrugations of adjacent panels to form a substantially continuous helical V-shaped groove extending lengthwise of the peripheral Wall, the said corrugations having side walls of a width equal to the said predetermined dimension and at least one side wall of each V-shaped corrugation of one panel being spaced from the corresponding side Wall of the mating corrugation of an immediately adjacent panel to form therewith a slot having a width equal to said predetermined thickness and a length equal to the width of the side wall and correspondcf 3,123,216 1C6 Patented Mar. 3, 1964 ing to the said predetermined linear dimension, whereby only those letters or similar articles having a thickness less than the width of a slot and at least one linear di mension less than the length of the slot, are discharged through the slots.

Preferably but not essentially each panel is pivotally supported for limited rotation about an axis extending longitudinally thereof to permit the width of the slot between adjacent panels to be varied. Conveniently the width of the slot is increased when the panels approach their uppermost position so that any article which may have become lodged within a slot will be released to fall back into the drum.

One embodiment of the invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a longitudinal section of a segregating drum according to the invention, the section being taken along the line 1-1 of FIGURE 2, and

FIGURE 2 is a section taken along the line 11-11 of FIGURE 1.

As shown in the drawings the drum comprises annular end plates 1 and 2 secured together in spaced relation by tie rods 3 to form a cylindrical cage. The peripheral wall of the drum is formed by a plurality, for example, eight elongated panels 4 extending lengthwise of the drum and supported in the end plates 1 and 2 in the manner hereinafter described. Each panel is formed with a plurality of V-shaped corrugations 5 extending transversely thereof and inclined with respect to the longitudinal axis thereof so that the corrugations of the respective panels form a continuous substantially helical groove extending the length of the drum. Each panel 4 is supported by an angle iron member 6 extending lengthwise across the tops of the corrugations and secured thereto as by welding, the member 6 having at each end a bracket 7 extending at right angles thereto and pivotally supported on a pivot pin 8 secured in the respective end plate. The panel is thus pivotally supported between the end plates 1 and 2 and the member 6 is offset from the longtudinal centre line of the panel as clearly shown in FIGURE 2 so that the panel is weight-biassed to swing about its pivotal axis. Thus and as will be clearly seen in FIGURE 2 each panel is weight-biassed to swing in an anti-clockwise direction about its pivots 8 when in the upper positions, and is weight-biassed to swing in a clockwise direction when in the lower positions. Light tension springs 9 connected at one end as at 10 to each end of a panel and at the other end by means of pins 11 to the corresponding end plate, oppose the anti-clockwise swinging of the panels when in the upper positions. The extent of the swinging movement of each panel is determined by stop pins 12 and 13 secured in the end plates and adapted to engage the brackets 7 to limit the pivotal movement thereof about the pins 8.

The longitudinal marginal edge portions of the panels overlap one another with their corrugations in mating relation and owing to the relative angular displacement of adjacent panels, the side Walls of the corrugations of one panel are spaced from the side walls of the mating corrugations of an adjacent panel to form slots 17 between the respective side walls of the mating corrugations.

It may also be arranged that the mating corrugations of adjacent panels are relatively displaced longitudinally of the drum so that between any two adjacent panels one side wall of each corrugation of one panel engages the corresponding side wall of the mating corrugation of the adjacent panel while the other side Walls of the mating corrugations are spaced lengthwise of the drum to define the slots 17 between adjacent panels. The slots 17 have a length therefore corresponding to the width of the side walls of the corrugations and a width determined by the spacing of the mating corrugations of adjacent panels. There are thus a plurality of slots 17 spaced lengthwise of and around the periphery of the drum, the number of slots being determined by the number of panels and the number of corrugations in each panel.

The drum is mounted for rotation about its axis by rollers 14 which engage the periphery of the end plates and at least one of which is driven by an electric motor 1'5 having a driving connection therewith indicated in broken line at 16.

In operation of the segregating drum, the drum is rotated by means of the electric motor and a stream of mixed postal mail is fed into the drum through the aperture in the end plate 1 so that the items of mail fall into the revolving drum and are propelled towards the other end of the drum by the action of the helical groove formed by the corrugations 5. The letters or similar small items of mail fall into the corrugations of the lowermost panels and each letter or item is supported by a wall of a corrugation in position for discharge through the corresponding slot 17 when the panel upon which the letter or similar small item rests is carried upwardly by rotation of the drum, the letter or item then sliding down the corresponding wall of the corrugation and through the slot providing of course that it is of a thickness less than the width of the slot and that its linear dimension presented to the slot is less than the length of the slot.

The larger items of mail ride on top of the V-shapetl corrugations and are fed towards the other end of the drum by the action of the helical groove and are discharged through the aperture in the end plate 2. Since the larger items ride on the top of the corrugations the smaller items which fall into the corrugations are not trapped or jammed by the weight of the larger items. Suitable vanes or heaters may be provided in the drum to assist in moving the larger items towards the discharge end.

When a letter falls into one of the V-shaped corrugations it lies flat against one of the side Walls thereof and if the letter is of a size such that it extends above the upper edge of the wall it will not of course be able to slide through the slot and it will be carried upwardly by the panel upon which it rests until it falls again to the bottom of the drum to rest in a further corrugation. In falling it will probably the reorientate'd, and if in its reorientated position it does not extend above the upper edge of the side wall of the further corrugation it will then be discharged through the slot.

By reason of the pivotal mounting of the panels the width of the slots is increased when the panels approach the uppermost position and this enables any letter which may have become lodged in a slot to thereleased therefrom. Thus and referring to FIGURE 2 it will be seen that a panel is the lowermost position such as the panel indicated at 4a is urged by its unbalanced weight and by the tension of the spring 9 to rotate in a clockwise direction so that the bracket 7 engages the stop pin 12 and in this position of the panel the slots 1'7 between the panel 4a and the immediately adjacent panel 41) will have the required width. As the drum rotates anti-clockwise as viewed in FIGURE 2 and as the panels approach the uppermost position they are swung anti-clockwise about their pivots 3 due to their unbalanced weight which evercomes the tension of the spring 9. The tension of the spring 9 is made such that only when a panel is nearing the uppermost position, is the unbalanced weight sufficient to overcome the tension of the spring and in the uppermost position therefore the panel swings to the position shown in broken line at 4d thereby to widen the slots and permit any letters lodged thereto to fall to the bottom of the drum.

In order to grade the output of the segregating apparatus various arrangements of the drum are possible.

Thus for example a drum of a given length may have the same pitch helical groove throughout but with the walls of the corrugations arranged to be progressively widened thereby to give slots which are progressively longer. ternatively the pitch of the helical groove may increase along the length or" the drum. Again, a number of drums differing from one another only in the size of their slots may be operated in tandem, or a composite drum may be used consisting of a first portion having panels arranged according to the invention and a second portion having fiat uncorrugated panels defining elongated slots for discharging large letters of the required thickness.

Furthermore the pitch or angle of the helical groove may be varied and it may be either single start as shown in the drawing or multiple start.

Furthermore and due to the propulsion of the items through the drum by the helical groove the drum can even be arranged with its axis inclining upwardly from the charging end.

I claim:

1. Apparatus for segregating from a quantity of letters or similar flat articles those letters or similar fiat articles of less than a predetermined thickness and having at least one linear dimension less than a predetermined dimension, comprising a drum shaped receptacle for containing said quantity of letters or similar flat articles, and supported for rotation about its axis and means for rotating the drum, the said drum having a peripheral wall formed by a plurality of elongated panels extending lengthwise of the drum and overlapping each other along their longitudinal edges, each panel being formed with V-shaped corrugations extending transversely thereof at an angle inclined with respect to the longitudinal axis of the panel and having side walls of a width corresponding to the said predetermined linear dimension, and mating with corrugations of adjacent panels to form a substantially continuous helical V-shaped groove extending lengthwise of the peripheral wall, at least one side wall of each V-shaped corrugation of one panel being spaced from the corresponding side wall of the mating corrugation of the immedia ely adjacent panel to form therewith a slot having a width equal to said predetermined thickness and a length equal to the width of the side wall and corresponding to the said predetermined linear dimension, whereby only those letters or similar fiat articles having a thickness less than the width of a slot and at least one linear dimension less than the length of the slot are discharged through the slots.

2. Apparatus according to claim 1 wherein each panel si supported on end plates for limited rotational movement about an axis extending longitudinally of the drum thereby to permit the width or the slots to be varied.

3. Apparatus according to claim 2 wherein the said axis of rotation of the panel isotiset transversely of the panel from the longitudinal axis thereof whereby the panel is weight-biassed to rotate about its axis of rotation so that as the drum is rotated and when the panel approaches its uppermost position it is biassed to rotate in one direction and when the panel approaches its lowermost position it is biassed to rotate in the other direction.

4. Apparatus according to claim 3 including stop means for limiting the extent of rotation of each panel in said one and the other direction and arranged so that when a panel is rotated in said other direction the width of tne Slots between adjacent panels is equal to said predetermined thickness and when the panelis rotated in said one direction the width of the slots is increased to permit any letter or similar flat article that has become lodged in a slot, to be released therefrom.

5. Apparatus according to claim 4 including spring means biassing the panel to rotate in said other direction,

5 the bias of the said spring means being insuflicient to overcome the Weight bias of a panel when in its uppermost position.

6. Apparatus according to claim 1 wherein the drum has end plates and is supported upon rollers engaging each end plate, at least one of which rollers is driven for example by an electric motor thereby toelfect rotation of the drum.

References Cited in the file of this patent UNITED STATES PATENTS Moran May 27, 1953 FOREIGN PATENTS Denmark Jan. 15, 1920 Great Britain Dec. 2, 1959 

1. APPARATUS FOR SEGREGATING FROM A QUANTITY OF LETTERS OR SIMILAR FLAT ARTICLES THOSE LETTERS OF SIMILAR FLAT ARTICLES OF LESS THAN A PREDETERMINED THICKNESS AND HAVING AT LEAST ONE LINEAR DIMENSION LESS THAN A PREDETERMINED DIMENSION, COMPRISING A DRUM SHAPED RECEPTACLE FOR CONTAINING SAID QUANTITY OF LETTERS OR SIMILAR FLAT ARTICLES, AND SUPPORTED FOR ROTATION ABOUT ITS AXIS AND MEANS FOR ROTATING THE DRUM, THE SAID DRUM HAVING A PERIPHERAL WALL FORMED BY A PLURALITY OF ELONGATED PANELS EXTENDING LENGTHWISE OF THE DRUM AND OVERLAPPING EACH OTHER ALONG THEIR LONGITUDINAL EDGES, EACH PANEL BEING FORMED WITH V-SHAPED CORRUGATIONS EXTENDING TRANSVERSELY THEREOF AT AN ANGLE INCLINED WITH RESPECT TO THE LONGITUDINAL AXIS OF THE PANEL AND HAVING SIDE WALLS OF A WIDTH CORRESPONDING TO THE SAID PREDETERMINED LINEAR DIMENSION, AND MATING WITH CORRUGATIONS OF ADJACENT PANELS TO FORM A SUBSTANTIALLY CONTINUOUS HELICAL V-SHAPED GROOVE EXTENDING LENGTHWISE OF THE PERIPHERAL WALL, AT LEAST ONE SIDE WALL OF EACH V-SHAPED CORRUGATION OF ONE PANEL BEING SPACED FROM THE CORRE- 